They are a class of drugs used to treat various cardiac pathologies such as hypertension, heart failure, angina pectoris, arrhythmias or hypertrophic cardiomyopathy. The regulation of the nervous system is carried out by means of substances called catecholamines (adrenaline and noradrenaline).

To exert their action, these substances have to bind to receptors located on the surface of cells, called adrenergic receptors. One of these receptors is the so-called beta-adrenergic receptor, which is found primarily in the heart, arteries and lungs. When this receptor is stimulated with the arrival of catecholamine, the heart rate, blood pressure and cardiac contractility are increased.

A beta-blocker is a drug that blocks the beta adrenergic receptor, in such a way that it prevents the binding of catecholamine and prevents its stimulation. The final effect is a reduction in heart rate, blood pressure and contractility (strength of the heart) by favoring cardiac diastole (filling) and thereby improving heart function and blood flow to the coronary arteries.